show that only shows non-default values

[aplavin]

Would be nice to omit default values in show() of structs that have defaults:

julia> @kwdef struct S
       a = 1
       b = 2
       end

julia> @batteries S kwshow=true

julia> S()
S(a = 1, b = 2)  # could be S()

julia> S(b=10)
S(a = 1, b = 10)  # could be S(b = 10)

Especially useful for large structs, but nice even with only a couple of parameters.

[jw3126]

Great suggestion.

[jw3126]

Actually this seems tricky. How do we know what is a default value?

[aplavin]

Hmm, yeah, unfortunately @kwdef doesn't provide a public way to access defaults. Only extracting them from the constructor signature... Or upgrading @kwdef :)

[aplavin]

May be added soon: JuliaLang/julia#55599.